In my co-pending patent application, Ser. No. 07/682,499 filed Apr. 8, 1991, now the U.S. Pat. No. 5,139,090 of which this application is a continuation-in-part, it is pointed out that rotating the production tubing string respective to the sucker rod and casing string while concurrently placing the production tubing string in tension reduces the severity of wear of a curved tubing string by reducing the contact area between the tubing string and rod string. This redistribution of wear between the sucker rod string and the tubing string is very desirable for it reduces the maintenance cost of the well, and additionally reduces the cyclic working (tension changes) of the production string and thereby overcomes many problems associated with crooked wellbores. Moreover, such an arrangement provides the unexpected benefit of enhancing the protection of the sucker rod and production tubing afforded by corrosion inhibitors which is realized because the rod and tubing rubbing surfaces are continually moved away from the contact area therebetween, thereby progressively treating the entire surface of the rod and tubing string each rotation of the tubing string.
The present invention comprehends improvements over the co-pending patent application by the provision of a new anchor device having a mandrel rotatably extending therethrough and connected to the rotating production tubing string by which the production tubing string is placed in tension while being rotated from the surface, thus greatly simplifying the production equipment required for producing the well.